<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Title</title>
</head>
<body>
<form id="form1" action="">
<div><strong>这是a.html页面<strong>
<iframe src="b.html" width="500px" height="300px"></iframe> </strong></strong></div>
</form>
</body>
</html>